The conventional cylinder or round shaped door knob can be extremely difficult to operate when a good grip of the knob is interfered with for any reason. For example, a wet or oily door knob may be quite difficult to turn. In addition, when a person does not have a free hand as in the case of carrying packages or the like, it is sometimes difficult to open a door.
Further, in the case of handicapped persons, the person may lack the gripping power required to operate the door knob or lack the wrist mobility necessary to turn the knob. Further, in the case of a handicapped person, particularly amputees, the artificial limb fitted to the handicapped may not be compatible with turning of door knobs.
For these and other reasons, lever operated door knobs are finding increased popularity and are specified in many cases for use by handicapped persons in places where handicapped persons are employed or are present.